Field of the Invention
The present invention relates generally to the field of drywall corner trim and more particularly to a drywall corner trim with adhesive.
Description of the Prior Art
Drywall corner trim is known in the art and has been used for years to finish interior and exterior corners in drywall construction. Classical corner beads were metal or vinyl strips with some sort of flange, through which mechanical fasteners are driven, and a bead running along the center of the material that allowed the corner to be finished with a mastic, like drywall mud.
Newer materials like flextrim pieces overcome many of the disadvantages of metal beads such as requiring large amounts of mud to finish, denting, rusting and other destructive effects. Flextrim usually contains a plastic center piece or base with paper flanges. The plastic may be grooved along the centerline to provide a flexible hinge where the flanges can be set at any angle. A typical flextrim product is described in U.S. Pat. No. 6,148,573. An improvement of the flextrim product is stepped flanges that make it boxable, that is that both flanges can be wet-mudded without mud overlapping from one flange to the other. Boxable flextrim is described in U.S. Pat. No. 6,779,313. U.S. Pat. Nos. 6,148,573 and 6,779,313 are hereby incorporated by reference.
It is known in the art that many corner bead and trim materials are difficult to apply using mechanical methods (for example screws, staples & nails) of attachment and are very susceptible to damage after application and finishing, usually due to impact or building movement. The damage can be in the form of cracked edges at the flange edge as the dried mud cracks during impact or building movement. This can result in the flange delaminating away from the wall surface.
To try to mitigate this type of damage associated with metal or vinyl corner bead, installers commonly use separate adhesives to better bond the corner bead material to the drywall corner, and they may apply mesh material over the flange edge of the corner bead after installation over which they apply their first layer of mud. The most commonly used adhesive is a spray-on type currently available. The mesh material is usually fiberglass, and may have a different adhesive applied to the wall-facing side.
It would be advantageous to have a corner trim material that decreases application time, decreases the need for expensive tools, decreases installer skill required to use drywall mud, and increases the finished bond integrity of the corner, as well as decreasing the susceptibility to damage. This material could be of the type that allows an installer to take a pre-cut piece of the material and stick it to the wall via a layer of adhesive already included on the wall facing side of the material. The adhesive can rapidly create a permanent bond between the corner trim material and the drywall. Drywall mud or other mastic material applied after the product is bonded to the wall can migrate through openings or holes in the flanges and create a secondary bond to the wall in a very strong, damage-resistant fashion. The moisture in the mud may also further activate the adhesive included on the wall side of the flextrim material if the adhesive is a water activated adhesive.